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From temperature change to length change.

Estimate free linear expansion or contraction using your own coefficient. See the signed length change and the final length together.

No installation or accountCalculated in this tabDownload your result

01 · Your inputs

Free, unrestrained expansion only. Use a verified coefficient for your material and temperature range. The loaded example is illustrative.

Microstrain per kelvin: enter 12 for 12 × 10⁻⁶/K. User-supplied constant coefficient; no material database. Zero and negative coefficients are accepted.

Final minus initial temperature. Positive means warming; negative means cooling. Changing the unit converts the entered interval. This is a temperature difference, not an absolute temperature.

Decimal point or comma and scientific notation accepted; no thousands separators. Results update as you type.

02 · Your result

Signed length change ΔL

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Calculated values — up to 15 significant digits; display precision is not measurement accuracy

Positive ΔL means expansion; negative ΔL means contraction. A negative coefficient reverses the usual warming and cooling behavior.

Inputs stay in this tab. Nothing is uploaded or saved automatically.

Understand the calculation

Formula & assumptions
ΔT(K) = ΔT(°C) = 5/9 × ΔT(°F)
ΔL (mm) = α (µm/m/K) × 10⁻⁶ × L₀ (mm) × ΔT(K)
L₁ = L₀ + ΔL

A homogeneous, isotropic solid undergoes a uniform temperature change with no restraint. Its linear expansion coefficient is treated as constant over the interval. For the illustrative inputs, 1000 mm × 12 × 10⁻⁶/K × 50 K gives 0.6 mm expansion and a final length of 1000.6 mm.

With positive α, warming expands and cooling contracts. Zero α or zero ΔT produces no length change. A negative α reverses the direction.

Sources & limitations

Temperature gradients, phase changes, anisotropy, restraints, stress, forces and joint clearances are excluded. Absolute temperatures are not entered, so this tool cannot check absolute zero or material service-temperature limits. Check the actual temperature range and coefficient independently.

Warnings appear above 1% absolute strain or a 100 K absolute temperature interval. These are calculator screening thresholds, not standards or material limits. No warning does not establish validity. A nonpositive final length is rejected.

Alkoc Labs calculation engine v0.5.0. Educational and preliminary engineering use only. This calculation provides no design approval or safety assessment.

Keep the assumptions with the result.

The JSON export includes inputs, units, results, assumptions, warnings and the source link. Inputs are lost on reload or when the tab closes.

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